He said National would campaign on its strong record in government, with its handling of the economy at centre stage.

“New Zealand is well placed compared to many other countries. That’s down to the hard work of households and businesses across the country, backed by the National-led Government’s clear and successful plan for our future.

“The challenge for our country now is to sustain that growth and build on it to deliver more again for all New Zealanders.”

Asked to sum up the election in one word, English replied, “Growth”.

He believed it was unlikely immigration would be a major issue at the election, with all forecasts indicating there would be a slowdown in the number of immigrants arriving.

English said National’s preference was to work with its current partners – UnitedFuture, ACT, and the Maori Party.

He ruled out any deal with Labour or the Greens but said a coalition with NZ First was a possibility, despite calling them an “unlikely partner”.

While describing Winston Peters’ party as “an inward-looking party who believe in a closed-up New Zealand”, English would not “rule in or out” choosing Peters as deputy prime minister.

Asked whether deals with ACT leader David Seymour and UnitedFuture leader Peter Dunne in their respective Epsom and Ohariu electorates would continue, he said discussions were still ongoing but it was unlikely that would change.

“I think you could expect existing arrangements that have worked would continue to underpin a stable National-led government.”

“Good policy and a general election” would get National voters to the polls, improving on the party’s poor performance in recent by-elections, English said.

Little said the party was “ready and raring to go so we can change the Government and build a better New Zealand”.

Little said the party’s priorities would be the housing crisis, improving access to healthcare, and “building the world-class education system parents expect for their kids”.

The party had learned “a heap of lessons” after its disastrous 2014 result, he said.

“One is to be very clear to voters about what the make up of a Labour-led government would look like. The other is to be clear about the priorities we stand for – giving people the chance of homeownership again who presently have no hope at all for that.”

English’s claims that National was strongest on the economy did not stand up to its record, Little said.

“Let’s look at what today’s record shows us – higher unemployment compared to this time last year, stagnant wage growth…if that’s economic success we’re in real trouble.”

NZ First leader Winston Peters said the election date “suits us fine”, while Green Party co-leader James Shaw said his party was “more energised and more prepared than we’ve ever been”.

“The election’s got to be about prosperity and they’ve [National] got growth without prosperity…

“If he’s talking about growth in polluted rivers, growth in house prices, growth in debt, those things aren’t going away.”